Moisture management double face woven fabric

ABSTRACT

A process for manufacturing a differential function, double-face fabric, comprises the steps of a) providing two different yarns, the first yarn exhibiting hydrophilic behavior and the second yarn exhibiting hydrophobic behavior; b) providing a knot yarn; and c) producing a fabric by simultaneously weaving said two yarns, and linking them with said knot yarn.

FIELD OF THE INVENTION

The present invention relates to the manufacture of a noveldifferential-function woven clothing article. More particularly, theinvention relates to a breathable fabric comprising a water-repellenthydrophobic external layer, and internal hydrophilic layer, whereinwater or sweat moisture is diffused out through the internal layer. Theinvention further relates to garments made of such fabric.

BACKGROUND OF THE INVENTION

Clothing fabrics may be produced for various objectives and needs.Traditionally, it is common in the art to provide formal and casualgarments for outwear as monofunctional fabrics which have one dominantproperty, for example; heat retention or wind protection provided bynatural or synthetic yarns of weaves and knits. Another traditionalapproach is to provide fabrics with additive function; to improve thefunctionality of fabrics by the application of variouschemicals/polymers and by adding certain features to the garment, forexample: water repellence, antibacterial or UV protection, flameretardancy, shrink-proofing, etc.

Another common approach is to modify the fabric properties by coating orlamination by using various polymers. However, fabric that issingle-layered, may offer only one function, or additive functions, butnot contrasting chemical function such as hydrophobicity andhydrophilicity. A known method used to achieve such result is to providea multilayer fabric by introducing a membrane between two layers,leading to different functionality of the two sides of the multilayerfabric.

U.S. Pat. No. 5,787,503 teaches the joining together of two differentlayers, one hydrophobic and the other hydrophilic, by knitting, to forma double-layer sweater, wherein the linking between the two layers is apolygonal-shaped quilting stitch pattern forming insulating pocketsbetween the layers. The purpose of this configuration is to manufacturea sweater that keeps the wearer dry as well as warm.

A different approach for a double-layered garment is described in U.S.Pat. No. 6,128,783, which teaches the production of a reversible sweaterhaving one layer composed of knit fabric, and the other of micro-fiberfabric. According to this patent, the wearer may select which side ofthe sweater to wear according to weather conditions.

The use of a dual-function garment has been considered also for medicalapplications. U.S. Pat. No. 6,148,444 discloses the use of a sweater forhemodialysis patients. According to this patent, the sweater is warm andkeeps the patient dry at the same time, and contains a series ofopenings that will allow access to grafts or fistulas, as well ascatheters, during medical procedures.

It is a purpose of the present invention to provide a combination ofdesired properties in a garment generating a double-layered fabric,without introducing any membrane between the two layers, choosing twocompatible layers, wherein one face of the fabric has a desiredproperty, and the other has a different desirable property, and thensuperimpose the two layers together.

It is another purpose of the present invention to provide an outwearthat combines desired properties in a comfortable, economic and simpleto manufacture manner.

It is still another purpose of the invention to provide a two-layeredfabric, comprising an external face, designated as face-side, made fromwool alone or wool wrapped with nylon or cellulosic yarn, and aninternal layer, designated as back-side, made from polyester. Theface-side is water-repellent, and prevents permeability of waterdroplets inside the fabric while the back-side is hydrophilic,water-absorbent allowing the perspiration to diffuse through the fabricoutside, and then to evaporate.

It is a further object of the invention to provide a breathable fabric,moving moisture away from the skin.

It is a further object of the invention to provide a process for themanufacture of a light clothing or garment possessing the abovementioned properties.

Other purposes and advantages of this invention will become apparent asthe description proceeds.

SUMMARY OF THE INVENTION

The invention relates to a process of manufacturing a differentialfunction fabric, which can be further used to prepare a breathablegarment, which can aid moisture evaporation from the skin. In oneaspect, the invention is directed to the preparation of a double facefabric comprising the steps of dyeing, chemically treating two differentyarns, simultaneously weaving the yarns in a warp and weft, and linkingthem by a knot yarn. The knot yarn is preferably—but nonlimitatively—made from nylon 66.

According to a preferred embodiment of the invention, the first of thetwo yarns is made from wool alone, or from wool wrapped with nylon 66filament, or cellulosic yarn, or wool wrapped with covered elastane orcellulosic yarn with elastane.

In this specification, the term “elastane” (also known as “Spandex”) isused to designate man-made elastic fiber, consisting of polyester diol,or polyether diol with diisocyanate.

According to another preferred embodiment, the second yarn is made fromspun or filament polyester selected from polyethyleneterephthalate(PET), polymethyleneterephthalate (PTT), or polybutyleneterephthalate(PBT).

According to a preferred embodiment of the invention, a double facefabric which has differential functionality is provided, comprising twolayers, a face side which is hydrophobic and water-repellent, and a backside which is hydrophilic, and water-absorbent.

Preferably, the face side is wool or wool-based or cellulosic-based, andthe back face is polyester. According to another aspect of theinvention, the wool yarn or cellulosic yarn is treated withfluorocarbons, and the polyester yarn is treated with polysiloxanes.

The invention will be further understood through the followingillustrative and non-limititative examples.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a flow-chart of the manufacturing steps of adifferential-function fabric;

FIG. 2 is a schematic illustration of a cross-section of a double-layerfabric.

DETAILED DESCRIPTION OF THE INVENTION

As stated, the invention relates to a process for the manufacturing of afabric comprising two layers, to a fabric made thereby and to breathablegarments made of the fabric.

In order to achieve the desired effect, a fabric is produced from twodifferent yarns through spinning, weaving, dyeing and chemicaltreatments, and through the weaving process these two layers are knottedby a third yarn to produce the desired product. The production steps ofan illustrative and non-limitative process are schematically illustratedin FIG. 1, and are as follows:

-   -   a) A fabric consists of two basic yarns 1 and 2 each made from a        different material (in the example of FIG. 1, wool and        polyester);    -   b) The knot yarn is made from a third material 3, which can be        the same as, or different from, the material of yarn 2;    -   c) All three yarns are dyed (4) separately by known methods for        wool, polyester and nylon;    -   d) The two yarns are woven together (5) in a double-face weave,        in a warp and weft fashion, and are joined simultaneously by        knot yarn 3, which combines the warp yarns and introduce it into        the weft direction in a certain sequence to form woven fabric 5;    -   e) The woven fabric is then processed through a finishing step        (6), consisting, e.g., of wet treatment of the fabric through        washing, drying and continuous decatizing steps;    -   f) A light double-layered garment (7) is made from the fabric by        methods known in the art.

The wool yarn used in the present invention can be a yarn made from woolalone, or wrapped with nylon, particularly nylon 66 or can be made fromcellulosic yarn. The polyester yarn can be made of any suitablepolyester, and is preferably, but non limitatively, made ofpolyethyleneterephthalate (PET). The wool yarn or cellulosic yarn servesas the face-side of the fabric, and the polyester yarn is provided forthe back-side of the fabric.

According to a preferred embodiment of the invention the wool yarn isdyed in an acid dye bath at about 100° C. (or any other suitabletemperature) with an acid dye, or the known metal complex 1:2 dyestuf,or by a reactive dyestuff, such as alpha-bromoacrylamide, orvinylsulfone derivatives, followed by cleaning in order to improve thewet fastness properties of the yarn, and then rinsed with water.

According to a preferred embodiment of the invention the cellulosic yarnis dyed in an alkaline bath mainly with cold or warm reactive dyes (monoor bifunctional dyes) at a temperature range of 50° C. -80° C., followedby multiple rinsing and soaping cycle to improve the wet fastnessproperties of the yarn.

In order to achieve the desired water-repellency of the final product,it is important to chemically treat the wool or cellulosic yarn. This isobtained by immersing the wool or cellulosic yarn in a water bath, andthen by adding 4-5 wt % of a fluorocarbon derivative. In an illustrativeand non-limitative process this step is carried out at about 40° C. forabout 20 minutes, and then the solution is drained. Thus, by thisprocess, the yarn becomes hydrophobic. The yarn is checked forhydrophobicity by methods known in the art, which are not discussedherein, for the sake of brevity.

The polyester yarn is scoured prior to the dyeing process by immersionin a solution of a mixture of non-ionic surface-active material and sodaash. In an illustrative and non-limitative process the solution is thenheated to about 60° C. at a rate of 2° C. per minute, and kept undersuch conditions for about 20 minutes.

The scouring removes the majority of the spin finishes and waxes formedin the spun polyester yarn. The yarn is then dyed in a dyeing bath, at115-130° C. by employing cationic/disperse dyestuffs.

In order to achieve a better water-permeability of the polyester yarn,it is important to increase its hydrophilicity. This can be done byimmersing the polyester yarn in a solution of 4-5 wt % of a functionalpolysiloxane derivative, prepared at ambient temperature. In anillustrative and non-limitative process the treatment is carried out atabout 40° C. for about 20 minutes, and the solution is then drained.Finally, the yarn is checked for its hydrophilicity and absorbency bymethods known in the art.

The knot yarn is made from polyamides, preferably (but non limitatively)from Nylon 66, and it is scoured prior to dyeing as describedpreviously. The dyeing is performed typically by a mixture of metalcomplex 1:2, or an acid dyestuff. The dyeing is typically carried out atabout 100° C. In order to achieve dark shades, the nylon yarn is fixed,by immersing it in a solution of 2-3% on weight of fiber (owf) of afixative agent, in an acetic acid medium at pH 5. In an illustrative andnon-limitative process the fixation step is carried out at about 50° C.,for about 20 minutes. Finally, the solution is drained. Since thefixation can sometimes interfere with the wicking force of the yarn, itis desirable to monitor this property, following the completion of thefixation.

The wool or cellulose and the polyester yarns are then woven on theRapier looms to form a double-layered fabric. The two layers are linkedtogether by the nylon knot yarn that combines the warp yarns of the twolayers, introducing it into the weft. In order to achieve a fabric(constructed from wool and polyester) that is machine-washable, the woolfiber can be treated by subtractive antifelt finish, for applicationslike oxidizing agents, and/or by additive antifelt finish (of polymerssuch as, polyurethanes, polysiloxanes).

The scouring process of the fabric consists of the application of 1-2 wt% non-ionic surfactant and is typically carried out at about 60° C., inan open-width washing machine having several compartments at anillustrative fabric speed of 15 m/min. It is important to dry the fabricat a temperature of less than 110° C., since higher temperatures mayinduce change in the fabric color and affect the functionality of thefabric. The process is been finalized by continuous decatizing. Thisstep is carried out in a decatizing machine, which does not containmetal surfaces.

FIG. 2 schematically illustrates a cross-section of the formeddouble-layer fabric, in which the face-side 21 is hydrophobic, thuscausing it to repel water in the direction indicated by arrow 22, andthe back-side 23 is hydrophilic, water-absorbent, causing body moistureto diffuse out through the two layers, in the direction indicated byarrow 24, and then to evaporate. The two layers of the fabric are linkedtogether by knot yarn 25.

According to a preferred embodiment of the invention, a wool orcellulosic yarn is woven together with a polyester yarn, and a knot yarnmade of nylon is used to link the two yarns, to produce a double-layeredfabric, in which the fabric external face is a wool or cellulosic layer,while its internal face is polyester, and these layers are knottedtogether by the nylon yarn.

The following examples serve to illustrate the invention, and are notintended to limit it in any way.

EXAMPLE 1

A double-layer fabric with differential functionality was manufacturedby the procedures described above, using the following conditions:

The weave was: double face plain weave, color woven, rigid fabric.Fabric weight was 200 gr/m².

The fabric composition was: 50% wool, 41% polyester, 9% nylon 66.

The yarns were as follows: first yarn: worsted wool yarn, count 40/1 Nm.This yarn was wrapped with nylon 66 filament, 11 dtex at 880 turns permeter (tpm). The wool micron was 20.5

The second yarn was made from polyester (Dacron 702, Coolmax Ex. Dupont)with yarn count of 50/1 Nm. The two yarns were woven together with aknit yarn, polyamide 66. The knot was introduced in the weft andcombined with warp yarns.

EXAMPLE 2

A double-layer fabric, weft stretch was manufactured by the proceduresdescribed above, using the following conditions:

The weave of the fabric; double face plain weave with weft stretch. Thefabric weight was 220 gr/m².

The fabric composition was: 58% wool, 37% polyester, 2% elastane, and 3%polyamide.

The yarns were: in the warp direction: worsted warp wool yarn count 40/1Nm. This yarn was wrapped with nylon 66 filament at 880 turns per meter(tpm). The second yarn was polyester, Dacron 702 in a yarn count of 50/1Nm at 1270 tpm. The knot yarn, polyamide 66, 78 dtex was used to combinethe two yarns in the weaving step.

Weft direction: the weft consisted of wool yarn, 40/1 Nm and polyesteryarn, 50/1 Nm. Both yarns were wrapped with elastane.

EXAMPLE 3

A bistretch double layer fabric was manufactured by the proceduresdescribed above, using the following conditions:

The weave of the fabric was double face plain weave with bistretchelasticity.

The fabric weight was 265 gr/m² and the fabric composition: 60% wool,35% polyester (Dacron 702), 11% nylon 66, and 4% elastane.

Yarns in a warp and weft as follows: worsted wool 40/1 Nm wrapped withelastane and polyester 50/1 Nm wrapped with elastane.

While embodiments of the invention have been described by way ofillustration, it will be understood that the invention can be carriedout by persons skilled in the art with many modifications, variationsand adaptations, without departing from its spirit or exceeding thescope of the claims.

1. A process for manufacturing a differential function, double-facefabric, comprising the steps of: providing two different yarns, thefirst yarn exhibiting hydrophilic behavior and the second yarnexhibiting hydrophobic behavior; providing a knot yarn; producing afabric by simultaneously weaving said two yarns, and linking them withsaid knot yarn.
 2. A process according to claim 1, wherein the weavingis performed in a warp and weft structure.
 3. A process according toclaim 1, wherein the first of the two different yarns is made from woolalone, or from wool wrapped with a nylon filament or from cellulosealone.
 4. A process according to claim 1, wherein the first of the twodifferent yarns is made from wool wrapped with covered elastane or fromcellulose with elastane.
 5. A process according to claims 3 and 4,wherein the yarn is treated with fluorocarbons selected fromfluoroalkanes, fluoroalcohols, fluoroglycols, fluoroanhydrides,fluoroacrylates, fluoroesters, and brominated fluoroalkanes.
 6. Aprocess according to claim 1, wherein the second of the two differentyarns is made from a polyester selected from polyethyleneterephthalate,polymethyleneterephthalate, polybutyleneterephthalate, modifiedpolyesters, or their mixtures.
 7. A process according to claim 5,wherein the yarn is treated with polysiloxanes selected from functionallinear or network polysiloxanes.
 8. A process according to claims 5 or7, wherein the treatment is carried out at about 40° C.
 9. A processaccording to claim 5 or 7, wherein the yarns are dyed prior to thechemical treatment.
 10. A process according to claim 1, wherein the knotyarn is made from polyamides selected from nylon 66, or polyestersselected from polyethyleneterephthalates.
 11. A process according to anyone of claims 1 to 10, wherein the fabric comprises a face side of woolor cellulose and a back side of polyester.
 12. A process according toclaim 11, wherein the back side is hydrophilic and water-absorbent. 13.A process according to claim 11, wherein the face side is hydrophobicand water-repellent.
 14. A double-faced fabric, comprising two layersmade by simultaneously weaving two different yarns and linking them witha knot yarn.
 15. A fabric according to claim 14, wherein one of the twodifferent yarns is a wool or wool-based yarn, or cellulose orcellulose-based yarn.
 16. A fabric according to claim 15, wherein thesecond of the two different yarns is a polyester yarn.
 17. A garmentmade of a fabric according to any one of claims 14 to 16.